Folks,
I, too, am seeing low 5GHz signal levels as reported by my laptop, at least, whilst the same laptop, in the same location, is seeing superlative 2.4GHz signal strength. We have no 5GHz phones and our neighbors are all at least 200 feet distant. At first, I thought it might be the notorious internal antenna connection problem, but I have a recent A2 and really doubt it's that.
Then, it hit me... My laptop is an old IBM T-41, what used to be a high-end model, and has a built-in a/b/g WiFi NIC made by IBM, itself. My feeling is that the problem is that the laptop has one internal antenna in the lid, and it's almost certainly optimized for 2.4GHz. Antenna pole length and orientation become more and more critical as the wavelength decreases, so I'd expect poor 5GHz performance when using receiver antennas optimized for 2.4GHz. Does this make any sense, do you think?
In any case, my serial number is F3SI187000155, just in case there's a problem I don't know about.
Regards,
Jeff